Effect on original feature: Overloaded functions which have differing code paths
for char* and constchar* arguments
will execute differently
when called with a non-const string's .data() member
in this revision of C++.
[Example 1: int f(char*)=delete;
int f(constchar*);
string s;
int x = f(s.data()); // ill-formed; previously well-formed — end example]